Bare plastic surfaces, such as polystyrene surfaces, typically do not resist non-specific protein binding or cell attachment. Surfaces modified with a dense and stable layer of polymers such as polyethylene glycol or hydrogels, such as dextran, are known to resist non-specific protein binding and cell attachment. In the prior art, in order to create a dense and stable layer of protective polymers or hydrogels on a plastic surface, the plastic surface was typically treated with a photochemical reaction to activate the surface or with prior art specially designed chemicals that have a high affinity to the relevant surface.